A detailed description of exceptions in python

This article introduces the exception details in python. Each exception is a class instance. these instances can be thrown and can be captured in many ways, this allows the program to catch and process errors.

>>> 1/0Traceback (most recent call last):  File "
 
  ", line 1, in 
  
       1/0ZeropisionError: integer pision or modulo by zero
  
 

Exception handling

You can use the try/try T statement to catch exceptions.

>>> def inputnum():    x=input('Enter the first number: ')    y=input('Enter the first number: ')    try:        print x/y    except ZeroDivisionError:        print "The second number can't be zero"        >>> inputnum()Enter the first number: 10Enter the first number: 0The second number can't be zero

Raise trigger exception

>>> class Muff:    muffled=False    def calc(self,expr):        try:            return eval(expr)        except ZeroDivisionError:            if self.muffled:                print 'Division by zero is illegal'            else:                raise            >>> c=Muff()>>> c.calc(10/2)Traceback (most recent call last):  File "
 
  ", line 1, in 
  
       c.calc(10/2)  File "
   
    ", line 5, in calc    return eval(expr)TypeError: eval() arg 1 must be a string or code object>>> c.calc('10/2')>>> c.calc('1/0')Traceback (most recent call last):  File "
    
     ", line 1, in 
     
          c.calc('1/0')  File "
      
       ", line 5, in calc return eval(expr) File "
       
        ", line 1, in 
        
         ZeroDivisionError: integer pision or modulo by zero>>> c.muffled=True>>> c.calc('1/0')Division by zero is illegal
        
       
      
     
    
   
  
 

Multiple Exception types

try:    x=input('Enter the first number:')    y=input('Enter the seconed number:')    print x/yexcept ZeroDivisionError:    print "The second number can't be zero!"except TypeError:    print "That wasn't a number,was it?"

Capture multiple exceptions at the same time

try:    x=input('Enter the first number:')    y=input('Enter the seconed number:')    print x/yexcept(ZeroDivisionError,TypeError,NameError):    print 'Your numbers were bogus...'

Object capturing

try:    x=input('Enter the first number:')    y=input('Enter the seconed number:')    print x/yexcept(ZeroDivisionError,TypeError),e:    print e    Enter the first number:1Enter the seconed number:0integer pision or modulo by zero

Catch all exceptions

try:    x=input('Enter the first number:')    y=input('Enter the seconed number:')    print x/yexcept:    print 'something wrong happened...'    Enter the first number:something wrong happened...

The above is a detailed description of exceptions in python. For more information, see other related articles in the first PHP community!